Versions 1.5.1 and 1.3.3 haven't quality improvements. Only fixes for bugs and some regressions.Version 1.1.34 has only some retuning and no quality improvements in LC-AAC encoder. And at least one regression was introduced in this version.Some quality improvements were made in 1.0.7.0. It's more than 3 years ago.

Versions 1.5.1 and 1.3.3 haven't quality improvements. Only fixes for bugs and some regressions.Version 1.1.34 has only some retuning and no quality improvements in LC-AAC encoder. And at least one regression was introduced in this version.Some quality improvements were made in 1.0.7.0. It's more than 3 years ago.

1. Do you make conclusion looking at the result of one sample? Encoder can do better on one sample but worse on others. That's actually happens with 1.5.4. Overall there is no quality improvement. Read the entire topic.

2.

QUOTE (matt_t @ Dec 23 2009, 17:28)

I haven't done a proper ABX test, but it's immediately clear (to me at least) that the new 1.5.1.0 encoder is MUCH better on this sample.

So you have made a conclusion basing on a single result without blind test.

1. Do you make conclusion looking at the result of one sample? Encoder can do better on one sample but worse on others. That's actually happens with 1.5.4. Overall there is no quality improvement. Read the entire topic.

2.

QUOTE (matt_t @ Dec 23 2009, 17:28)

I haven't done a proper ABX test, but it's immediately clear (to me at least) that the new 1.5.1.0 encoder is MUCH better on this sample.

So you have made a conclusion basing on a single result without blind test.

There is no point doing a blind test I know I will fail completely having got 16/16 with the previous version. I know what artifact I heard with the old version, and it has gone with the new one.

On some samples it got better, on some samples it got worse. Due to the big investigation that was invested in it, I believe that in average (among samples and listeners) it got just a bit better, but at the end it depends on what music you like to listen and if the changes are good for your ears or not.

On some samples it got better, on some samples it got worse. Due to the big investigation that was invested in it, I believe that in average (among samples and listeners) it got just a bit better, but at the end it depends on what music you like to listen and if the changes are good for your ears or not.

Regarding SBR encoding, what if you first encode the core stream, than turn quantized signal back to time domain and feed analysis QMF filterbank (its LF part) with the same signal it operates in decoder. Do you think this can have any positive effect?

There is no point doing a blind test I know I will fail completely having got 16/16 with the previous version. I know what artifact I heard with the old version, and it has gone with the new one.

Umm... A 16/16 would mean that you were able to effectively pick out which track was which during a blind ABX test. In other words, that is an ABX test that you "passed." Failing a test would be obtaining a much lower score and a higher probability that you were guessing. The whole "I know what I know" argument really has no place unless it can be backed up. What you think you remember hearing is not always accurate hence why downloading an older version of the Nero AAC encoder and testing it would be wise. Conducting a quick listen comparing to what you think you remember and relying on a two year old thread (which discussed a spoken word sample) is not enough to backup any claims. IgorC's post was also not dismissive of the Nero AAC developers. They were simply pointing out changes that have been applied to the encoder affecting output quality. Encoder updates do not always improve quality and many focus on stability issues. Igor's post would have been dismisive had they said "Nero AAC hasn't been updated in 3 years for LC-AAC encoding because the Nero devs are lazy bums who can't code to save their lives." Simply pointing out changes of a specific encoder over a period of time is not indicative of developer performance and they did not make an opinionated comment regarding that.